Safety device for elevators



ug- 23, 1932 E. N. BALDWIN 1,873,809

SAFETY DEVICE FOR ELEVATORS Filed June 16, 19304 Patented Aug. 23, 1932 UNITED STATES PATENT OFFICE EDWARD N. BALDWIN, 0E CHICAGO, ILLINOIS, AssIGNOR To wEsTINGHOUsE ELECTRIC Y y ELEVATOR COMPANY, A CORPORATION OE ILLINOIS .SAFETY DEVICE EOR ELEvA'roRs Application led .Tune 16, 1930. Serial No. 461,282.

My invention relates to improvements in safety devices for elevators and more particularly to safety coversfor automatic speed-governing devices.

The principal obgect of my invention resides in the provision of a novel protective cover for a speed-governing device which will protect `the governor from injury, or from unintentional operation and serve as a supportv for an interlocking switch element associated with said governing device.

, Another object of my invention is the provision of a novel protective cover for a speed-governing device which shall be simplein construction and economical to manufacture.V

Another object of invention isthe pro-v vision of a unitarycover and switch-element support which shall vbe compact, easy to assemble andA comprise a minimum number of parts. Y f j In the accompanying drawing, which illuistrates a preferred embodiment of this-invention and in which similar reference'numerals refer to similar parts in the dierent views, i

Figure 1 is an elevational view, partly in section, of my invention, showing an interlocking switch and cooperating governor parts, with the latter in vnormal operative position;

Fig. 2 is a sectional side view online II-II of Fig. 1: and l Fig. 3 is a side elevational view showing the position that the elements of-Fig. 1assume when the safety device is applied, andy the switch isopened. 1 y

In elevator practice, it is customary to employ a speed-governing device which, in the event the car over-speeds, isoperative to trip safety devices to cause interruption of the,

main control circuits and the clamping of governor rope against movement so thatit will be pulled away from the car toy set a safety-grip stopping device into operation to mechanically bring the carto `a safe stop.l

Such speed-governing devices 'are ordinarily placed Vin the elevator pent house in an open and unprotectedrposition. The various attendants whose duty it is to Vcare for theV elevator, frequently come into contact with elevator service until such time as the governor cable can be again attached to the car.

,In order to eliminate this sourceof trouble, I have provided a protective covering for governor which will serve a double purpose; viz, to protect the governor from accidental operation and, at the same time, provide a support for the Contact members of an interlocking switch which is adapted to be operated bythe governor to open the elevator power circuit. I am aware that a governing device has been used in the past tooperate an interlocking switch or similar device but Iv am not aware of any construction whereby one' device is-arranged to not only protect the governor but also to form a support for a' switch or any other like device. Y I As illustrative of the present invention, I have shown, in the accompanying drawing, a speed-governing device comprising a housing 1 constructed of a pair of side walls .2

and 3 to which are secured, in any suitable manner, as by welding, a top 4, a base 5 and a back 6. 4 Journaled in suitable openings in the side walls 2 and 3 is a shaft 7 upon which is rotatably mounted a sheave 8. The sheave 8 is restrained from lateral movement on the shaft 7 by means of suitable cylindrical fillersyI have illustrated a pair of governor` weights 17 and 18 secured upon'fsuitable bosses 15 and 16, projecting from the side of the sheave 8 at points on diametrically opposite sides of the shaft 7 The weights 17 and 18 should be pivotally secured tothe y sheave 8, as by means of suitable bolts 19 The rotation of the sheave. 8 will cause they governor weights 17 and 18 to be thrown outwardly by centrifugal forceY to causethe latching lugs 25, and `26- to project beyond the outerperiphery ofthe shea-ve 7. How-` evento normally restrain the governor arms against centrifugal force,v a pair of springs 27 and 28, inter-engaging the two governor weights, tends to hold the weights in a retractedipesition. The springs 27 and 28maybe of any suitable strength to take care of the-variation in speed and otherfactors which bear on the design of different types of elevators and governors therefor. A latch 29, to be engaged by the lugs v or 26 of the governor weights 17 and 18 when projected by centrifugal force as the governor shea-ve 8. is rotated' at a. speed? sufficiently great toV cause the weights 17 and. 18 to overcome the tension of springs 27 and 28, is suitably mounted upon a movable bracket comprising a pair of arms 30 and 31 located on oppositev sides of the governor sheave 8. The lower ends ofthe arms 30I and 3-1 arejournaledupon a bearing or shaft member 32 which, in turn, i's secured in suitable openings in the sidewalls 2 and3of'casing'1. Lateral movement of thel arms3 andi 31 is preventedf by means of spacing sleeves 33, 34 and` 35.

upper portion of the arms .30 and 31 by means ofa shaft 36 which passes through suitable openings inthe arms 30 and` 311- and latch member 29 and is secured against-displacement by means of suitable cotter pins- 37' and 38. 'lihe upper ends of` the arms 30'and 3f1 artJ connected, by means of a cross head 39, to which the arms 30 and 31 may besecured in any suitable manner as by welding. Mounted' upon: the same shaft 36 which supports the latch member 29 is a brakex shoev 40of`suchsizeand configuration as to engage the governor rope 14 when the latch member 29 is engaged. by the lugs 25v or 26- andi the arms V301and 31 moved to their operativeposi-l tion, as shown in Fig.L 3. It will be observed thatthevpoint of support 32 for the arms 30 and:314 is. in such relation to the axisof rota'- tion of the governor shaft 8 that, when. thelatchJ member 29 and arms 30- and' 31" are drawn tothe-right, the clamping shoe 40 is drawn intoia clamping engagement to act as Thelat'ch member 29fis pivotally attachedt tothea brake against the governor rope 13 to prevent further movement of the governor rope 14.

Secured upon the cross head 39, as by means of suitable insulating material 41, l have illustrated a bus bar or bridging member 42v which bridges a pair of contact members.. 43, and 44 when the latch member 29 and the arms 3,0 and .31 arein their normal eX- treme left-hand' position. The contact members 43 and 44 may be of any suitable character but I have illustrated the same as comprising Contact pieces pressed into bridging position, as; blyV meaaisof adjusting screws 45 and springs 46 which serve to secure the contact members to an insulating support 47 carriedI by the side wall 3I ofthe governor 1.

The contact members 45j may be connected in the main control circuit for the elevator car-through conductors'48 which pass through the conduit- 49a Tt w-ilil be apparent that a separation of the busbar l44` from the contacts 45', resultingA from an operation of the governor, will interrupt the circuit to the hoist` ing motor simultaneously with the application of tl'iecablebral're;

In the operation of the safety device, when the speed o-f the car becomes-excessive, the speed of rotaticn of the sheave 8- is corre,- spondingl'y increased thro-ugh its connection by the cable 14 to the car. At a predetermined limiting overspeed, dependent upon thetension` of; the springs 27' andj 28, thei governor'weights 117i and 18 will: be-movedoutwardlyv by centrifugal force-,. whereupon one of the latchingjlugs 25 and 26 will engage the;

latch 40, thereby movi-ngthe arms 292 and 30 forwardlyv untiltlieslfi-oe 41 engages thecable 14. Theinterloclring ofl'ug`25-or lug 26 with the latch 40E and the subsequentA gripping of the cable 14 by the shoe 41 provides a positiveI stop of`1 thecable, whereupona safety d'evice mountedupgon the elevator car is operated by movement of the carY relatively to thenow stationary cable. Operation of thesafety device brings the car to rest immediately.

Simultaneously, upon; fciwvard? movement of the arms 29 and 30, thebus bar144 will be brake armto cooperate with said l'atchingt portion, a shoesecuredtosaid'brale arm and adapted t'o move therewith toV engage said' gli cable, a switch, and means cooperating with said brake arm for opening said switch.

2. In a .speed-governing device, in combination, a sheave, a cable for driving said sheave, a pivoted arm associated with said sheave, said arm having a'latching portion, a pivoted brake arm, latching means on said brake arm and cooperating with said latching portion, a shoe secured to said brake arm and adapted to move therewith to engage said cable, a switch, a fixed support, the contacts oii' said switch being mounted on said support, said switch contacts being Operable by said brake arm.

3. In a speed governing device for an eievator, in combination, a sheave, a cable for driving said sheave, a pivoted arm associated with said sheave, a brake-arm, cooperating Iatching means on said pivoted arm andV brake-arm, a switch, and means on said brake-arm for opening said switch and engaging said cable.

In testimony whereof, I have hereunto subscribed my name this 12th day of- J une, 1930.

EDWARD N. BALDWIN. 

